Investigation on the factors that affect
the bounce of a ball
Aim:
To investigate the factors that affect the bounce of a ball.
Planning:
Scientific Knowledge:
In every day lives we come across a number of different objects that are bouncing, colliding and in motion. All these are attributable to the energy changes involved in the process thus obeying the law of conservation of energy. The law of conservation of energy states that 'energy can neither be created nor destroyed' and that the sum total of energy in this universe remains constant. This scientific method of looking at energy changes can be associated and implemented on a variety of simple things and one among them being observation of bouncing objects. This motivation has lead me to investigate, understand and analyse bouncing of a ball on a surface. However, understanding the bouncing mechanism is not as simple as it appears, because there are several factors involved during the bouncing action. For example, the material of the ball, the type and nature of surface over which it freely falls, frictional factors due to air resistance, temperature affecting the surrounding air molecules as well as during the ball-surface interactions.
Preliminary Investigation
Looking around practically made me notice a variety of different types and sizes of balls. There were golf balls, tennis balls, footballs, sponge balls, cricket balls, bouncy balls, etc. I observed them carefully and noticed that none were similar in any way. The cricket balls were the only ones made out of leather, the bouncy balls were made out of dense rubber, and the golf balls were made of plastic. I tried to test the bounce of these balls on different surfaces like carpeted flooring and wooden flooring. I found that each ball when dropped on these flooring was bouncing to different heights. I felt that each of these balls when dropped on a given flooring surface had different factors that influenced their bounce. Also I noticed that the ball being dropped constantly bounced almost at the same height. This made me feel that I could use this as my chosen experiment for further investigations.
As mentioned earlier, the bouncing of balls may look simple, but the energy conversions are quite complex. In simple terms, the work done during a bouncing ball system involves three possible energy sources, 1) Gravitational potential energy (energy due to its position) 2) Kinetic energy (energy due to its motion) 3) frictional energy (lost due to production of heat and sound). The ball acquires Gravitational Potential Energy because of its position and also the ball is working against the gravity to acquire this position. Kinetic energy is gained during the motion of the ball. The frictional energy is lost due to the production of heat and sound. In fact, the conversion of the potential energy results in the kinetic energy of motion until the bounce is over and this potential energy is regained as ball acquires the next position or height. However, on each bounce over a given surface energy of impact is transferred to the surface on which it bounces. Also energy is used up in over coming the air resistance. The energy of impact can be split into sound energy, heat energy or light energy (spark) in the case of very heavy balls (for ex. Iron balls striking iron plate surfaces). This can be totally called as frictional energy loss. The process of bouncing continues with frictional loss occurring on each bounce and this effect could be known as damping. Damping means the loss of height on each bounce on a given surface. The damping effect decreases until the ball attains the minimum potential energy. The damping effect influences the speed and so it tends to slow down the ball each time it impacts the surface. To observe this effect experiments were planned to drop large bouncy balls on different surfaces and to note the rebound heights.
the bounce of a ball
Aim:
To investigate the factors that affect the bounce of a ball.
Planning:
Scientific Knowledge:
In every day lives we come across a number of different objects that are bouncing, colliding and in motion. All these are attributable to the energy changes involved in the process thus obeying the law of conservation of energy. The law of conservation of energy states that 'energy can neither be created nor destroyed' and that the sum total of energy in this universe remains constant. This scientific method of looking at energy changes can be associated and implemented on a variety of simple things and one among them being observation of bouncing objects. This motivation has lead me to investigate, understand and analyse bouncing of a ball on a surface. However, understanding the bouncing mechanism is not as simple as it appears, because there are several factors involved during the bouncing action. For example, the material of the ball, the type and nature of surface over which it freely falls, frictional factors due to air resistance, temperature affecting the surrounding air molecules as well as during the ball-surface interactions.
Preliminary Investigation
Looking around practically made me notice a variety of different types and sizes of balls. There were golf balls, tennis balls, footballs, sponge balls, cricket balls, bouncy balls, etc. I observed them carefully and noticed that none were similar in any way. The cricket balls were the only ones made out of leather, the bouncy balls were made out of dense rubber, and the golf balls were made of plastic. I tried to test the bounce of these balls on different surfaces like carpeted flooring and wooden flooring. I found that each ball when dropped on these flooring was bouncing to different heights. I felt that each of these balls when dropped on a given flooring surface had different factors that influenced their bounce. Also I noticed that the ball being dropped constantly bounced almost at the same height. This made me feel that I could use this as my chosen experiment for further investigations.
As mentioned earlier, the bouncing of balls may look simple, but the energy conversions are quite complex. In simple terms, the work done during a bouncing ball system involves three possible energy sources, 1) Gravitational potential energy (energy due to its position) 2) Kinetic energy (energy due to its motion) 3) frictional energy (lost due to production of heat and sound). The ball acquires Gravitational Potential Energy because of its position and also the ball is working against the gravity to acquire this position. Kinetic energy is gained during the motion of the ball. The frictional energy is lost due to the production of heat and sound. In fact, the conversion of the potential energy results in the kinetic energy of motion until the bounce is over and this potential energy is regained as ball acquires the next position or height. However, on each bounce over a given surface energy of impact is transferred to the surface on which it bounces. Also energy is used up in over coming the air resistance. The energy of impact can be split into sound energy, heat energy or light energy (spark) in the case of very heavy balls (for ex. Iron balls striking iron plate surfaces). This can be totally called as frictional energy loss. The process of bouncing continues with frictional loss occurring on each bounce and this effect could be known as damping. Damping means the loss of height on each bounce on a given surface. The damping effect decreases until the ball attains the minimum potential energy. The damping effect influences the speed and so it tends to slow down the ball each time it impacts the surface. To observe this effect experiments were planned to drop large bouncy balls on different surfaces and to note the rebound heights.
